South African police have said they will not extradite the last remaining fugitive member of a 1970s extremist urban guerrilla group unless the US gives an assurance that he will not face the death penalty.

Hearst was kidnapped by, and became a member of, the SLA

James Kilgore, a former member of the Symbionese Liberation Army (SLA) which kidnapped publishing heiress Patty Hearst in the 1970s, was detained at his home in Cape Town, South Africa by members of the country's serious crimes squad and Interpol agents.

He is wanted in the US in connection with a 1975 bank robbery and murder, for which he could be sentenced to death.

However South Africa's legislation does not allow extradition to a country if the death penalty is applicable there for the alleged crimes, South African Justice spokesman Paul Setsetse said.

Mr Kilgore is expected to appear in court in Cape Town on Monday for an extradition hearing.

Notorious gang

Mr Kilgore's arrest comes shortly after four other SLA members pleaded guilty in a California court to shooting dead a bank customer during a raid.

Olson - former girlfriend of Kilgore's - was also on the run for 24 years

The SLA, which staged a series of bank robberies in the US in the 1970s, was most notorious for kidnapping Ms Hearst in 1973 and converting her to its cause.

Hearst, who was pardoned by former US President Bill Clinton, was the getaway driver in the crime, and in return for immunity from prosecution gave much of the evidence which led to the launch of a new inquiry into the case.

The four made a surprise appearance in a court in Sacramento in the US state of California on Thursday, where they pleaded guilty to the second degree murder of a 42-year-old woman during a robbery at bank in Carmichael, California.

Emily Montague, Bill Harris, Sara Jane Olson and Michael Bortin all received sentences of between six and eight years.

FBI spokesman Mark Mershon said Mr Kilgore had been arrested as his lawyer attempted to negotiate a plea-bargain similar to that of the other four, but the timing of the arrest had been a coincidence, Reuters news agency reported.

'Brought to justice'

Mr Kilgore's arrest on Friday followed a three-month investigation by the South African branch of Interpol, in which he was eventually tracked down to the Western Cape.

He was then apprehended in the luxury Cape Town suburb of Claremont, and did not resist arrest, although authorities said he seemed "surprised".

He is said to have admitted his identity when challenged by police officers.

"Terrorists can run and they can try to hide overseas. But in the end we will find them and bring them to justice," said US Attorney General John Ashcroft.

'Normal family'

Cape Town police spokeswoman Mary Martins-Engelbrecht said Mr Kilgore, 55, entered South Africa five years ago illegally and had been using the name Charles Pape.

She said he was working as a lecturer and researcher at the University of Cape Town, along with his wife and two sons.

Friends and neighbours of the couple expressed their amazement at Mr Kilgore's arrest, saying they seemed a normal and happy, if quiet family.

Other members of the group led similar lives in exile, such as Olson, a former girlfriend of Mr Kilgore's who renounced the group's militant, often violent philosophy to become a housewife in Minnesota before she was turned in.